Is it safe to have a 18' flat bottom sled out on the Columbia? I live way up north and am planning on buying a boat in the next year and sometime in the future hitting the river for some springs and was just curious if thats safe? Is that type of boat big enough? From what I have read, sleds can be the ideal way to go on rivers around the Northwest. Dont know if I can afford a jetboat right now but it sounds like they go real shallow to. Thanks :p